This invention relates to a gripping device for placing a component on a substrate, which gripping device comprises movable fingers and means for making the fingers move relative to each other so as to grip and release the component.
Such a device is known from DE-A1-3704402. This known device comprises two fingers which are arranged right opposite to each other and which can be moved towards each other and away from each other, and by means of which a component can be gripped and released.
It is an object of the invention to provide a gripping device in accordance with the first paragraph, by means of which components can be reliably and properly gripped.
To achieve this, the gripping device in accordance with the invention is characterized in that three fingers are present, which are arranged in a triangle and which are movable in parallel paths relatively to each other, and in that, viewed in the direction of movement of the fingers, the central finger can be moved in opposite directions with respect to the outer fingers. By arranging the fingers in a triangle, a component is gripped at three locations. As a result, the gripping operation is statically determined. The risk that rotational forces develop which act on the component is small. The component is gripped in a stable and reliable manner. Such a gripping device can be used to grip electric components, but also other components or objects, for example, framework-shaped accessories for electric components, which are to be placed on a substrate or printed circuit board.
A gripping device which is preferably used is characterized in that the distance between the fingers, viewed in the direction of movement of the fingers, is adjustable. By virtue of the adjustability, it becomes possible to adapt the distance between the fingers to the component to be gripped. In general, a component will be gripped on the outside thereof, i.e. the fingers will be moved towards each other in the gripping operation. It is alternatively possible, however, to move the fingers relative to each other such that a component can be gripped on an inside thereof, while for gripping and also for releasing the component, the fingers move in the same direction. The means for driving the fingers do not have to be adjusted.
A further embodiment is characterized in that each finger can be moved by means of two parallel leaf springs. By virtue thereof, the movement of the fingers is substantially without friction.
Yet another embodiment is characterized in that a cap is present which is arranged over the gripping device and which has a wall, wherein parallel grooves are formed through which the fingers project, and which wall serves as a stop for a component to be gripped. As a result, after a component has been placed on a substrate, it is clamped between the wall of the cap and the substrate, and only then the fingers are moved away from each other (or towards each other) to release the component. This leads to a reduction of the risk that, during placing the component, the component is slightly moved when it is released, which could result in an incorrect placement of the component.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.